1. Field
This invention relates generally to packaging for integrated circuits. More specifically, this invention relates to a method and arrangement for dissipating heat in an integrated circuit.
2. Background and Related Art
Integrated circuits generate heat to varying degrees. In typical applications, such heat must be dissipated to ensure that thermal effects do not impair the performance of, or even damage, integrated circuits. Thermal resistance is defined as temperature difference per unit power dissipated. When thermal resistance values are high, heat is not readily dissipated. In localized areas of a chip, such as a processor chip, heat fluxes may be very large, and temperatures may be very high. For instance, localized heat fluxes over the floating point area of a processor may be on the order of 350 W/cm2, and temperatures may rise as high as 130° C.
Various techniques have been employed to dissipate heat, including the attachment of thermal spreaders, integrated heat spreaders, heatsinks, or fans to integrated circuits. Such techniques involve external control of heat generated internally by integrated circuit components.
FIGS. 1A and 1B (Prior Art) are top and side views, respectively, of a structural arrangement 100. Arrangement 100 includes a semiconductor die 101 and a heat spreader 120 attached to a top face of die 101. Die 101, which may comprise a processor, includes local hot spots 110. Hot spots 110 may be associated with various mechanisms internal to die 101, such as a floating point unit, which generate localized heat. In arrangement 100, localized heat is dissipated away from die 101 only after the heat diffuses to the surface thereof and then diffuses to heat spreader 120.
As processor performance continues to increase, so too does heat generated by processor components. Existing cooling methods may not dissipate sufficient heat to obviate the heat-related problems identified above.
Therefore, what is needed is a method and arrangement for dissipating heat in an integrated circuit.